Remember soot and sweeps? They were great for the garden, says Brian Kidd

Q: My dad always had an allotment and used to sweep our chimney. The soot was used on celery plants at his allotment to keep slugs away. I found a box of dry soot in his shed and as I am growing celery now want to know how much to use. LB, Denvilles.

A: Young readers won’t know what soot is but it has been used with great success for centuries. A ring of soot (a tablespoon around every plant) will stop slugs eating the stems. An alternative is to use a tablespoon of soot in a gallon of water. Mix briskly and spray over the whole crop using a rose on the watering can. This will reduce leaf miner too.

Q: A friend gave me the article you wrote about growing runner beans in a growing bag. I live in a flat and there is a nice wide path under the wall. Is it too late to sow some seeds? LT, Buckland.

A: You will be successful if you plant them before the end of July. Your part of Buckland will look wonderful and I hope your neighbours will do the same.

Q: I have a little border which has perennial plants. There is a gap where I had a phlox but this disappeared. What would you plant there ? I would really like something pink which will flower all through the summer. Is there such a plant? SB, Bedhampton.

A: If you go to your garden centre you will see a selection of dahlias. You will be able to find the colour you would like and one which will not be too tall. Dahlias are non-stop bloomers all summer.

• Got a question for Brian? Click here and fire away.